Machine for bending and tempering leaf-springs



July 28, 1931, P. l- IOBRACHT' MACHINE FOR BENDING AND TEMPERING LEAFSPRINGS Fi led Dec. 12, 1928 s sheets-sheet 1 m m m July 28, 1931. ,P.HOBRACHT 5 3 MACHINE FOR BENDING AND TEMPERING LEAF SPRING6 Filed Dec.12, 1928 s Sheets- -Shaet 2 IN V EN TOR.

P. HOBRACVT ,3 MACHINE FOR BENDING AND TEMPERING\LEAF sPRINs July 28,1931.

Filed Dec.- 12, 1928 5 Sheets-Shae; 3

INVENTOR.

Patented July 28, 1931 UNITED STATES PATENT OFFICE PAUL HOBRACHT, orDUSSELDORF, GERMANY MACHINE FOR BENDI'NG' AND TEMPERING LEASE-SPRINGSApplication filed December 12, 1928 Serial No. 325,452, and in GermanyDecember 14, 1927.

Object of the invention is a machine for bending and temperingleaf-springs and such like, which renders possible an automatic andcontinuous working- In accordy'lfance with the invention any desirednumber of separate treatment devices may be disposed along the peripheryof a drum. The pre-heatedworkpieces are placed into the separatetreatment devices where they are bent andconsecutively passed through aplunger-bath, being thereby simultaneous- 'ly tempered and subsequentlyautomatically ejected and conveyed;

The accompanying drawings illustrate v the new device, in which Fig. 1represents a front-view, partly in section, of the apparatus. Fig. 2 isa side-view of bending-device in section.

Fig. 3 is a sectional end elevation of a pair of adjustable jaws and asupport for the saw blade.

Fig. 4 is a sectional side elevation of the parts shown in Fig. 3. j v

Fig. 5 is a top plan view of the same.

Fig. 6 is a View of the hydraulic actuating mechanism.

Upon a drum 1 and rotatably supported by standards 10 a plurality ofbending-devices for leaf-springs, eight for instance, are equallydistributed about the periphery of the drum. The bending-device consistsof two pressure-jaws, a fixed one 3 and a movthe same with the able one4:. The pressure-jaws support" pressure-bars 5, 6, between which theleafsprings are bent. The pressure-bars 5, 6 (see Figs. 3-5) areinterchangeable and separately adjustable with the aid of a screw 7 anda wedge "8 which can be displaced along a groove 9 on the wedge-shapedrear of each pressure-bar 5, for the purpose of being able to adjustthem in accordance with the desired degree of flexure. support eachleaf-spring 2 in its middle-p0- sition upon the pressure-bars,-a specialsupporting device has been provided. This consists of plates 15 fittedwith arms 11 on either side which are guided along eccentric grooves 12in two rings 14 adjustable by her-tubing ,20- and outlet-pipes '21.valve device for instance, consists of a cas- In order to means of alever 13. I The plates 15 are always occupy the middle-position oppositethe pressure-bars 5. The supporting-rails 17 are made narrow, in orderto permit the tempering medium, such as oil etc. to reach all points ofthe leaf-spring. For the purpose of enabling the spring-leaves to describe small longitudinal movements in conjunction with differences intension,-the ends of the pressure-bars are provided with rollers whichare supported by ball-bearings 37.

The actuation of the moveable pressurejaw 4 with the pressure-bars 6 forthe purpose of bending the spring-leaf 2 placed in position is effectedhydraulically by means of pairs of pressure-pistons 18, placed within'cylinder's19- on the pressure-jaw 4,-con nected with the frame or withthe pressurejaw 3. The pressure-cylinders 19 belonging together are eachconnected with a valve device by means of feeding-pipes or. rub- The ing22 carrying the piping establish-ing connection with the hollow shaft24, and containing within an axially adjustable piston valve connectedwith bars25, 26 projecting from the drum on either side. The

latter act conjointly with cam members 27, 28, causing the guide-pistonsto be displaced .to the left or to the right, whereby thepressure-cylinders 19 are either. placed under pressure or relieved ofpressure.

Every bending device has, moreover, been provided with anejecting-device for the completed work-pieces, which is made to consistof adjustable hook-arms 30 carried by a rock shaft-x29 and which catchrakelikein between the pressure-bars5, 6. The

'hook-arms are retained in their position by means of springs 31 and, onturning the drum 1 the bar 25 is made to alongthe cam surface 27, thuscausing the valve 22 adjusted to supply fluidpressure to actuate jaw 4and the spring-leaf 2 is bent. The.

latter is then by rotation of the apparatus plunged into the oil bath inthe tempering tankiin which theapparatus is arranged and tempered-"astheoperation is continued As soon as each bending-device has reached thepoint B after the drum has described a turn, the'jaw 4 will beopenedagain in consequence of the bar26 being moved by cam surface 28 andthecompleted spring will be released and ejected by the hook-arms 30.

1. In a machine for bending and tempering leaf-springs, the combination,wvith a rotatable carrier shaft or drum,iof relatively :fixed and-movable pressure jaws disposed parallel tosaid shaft or drum,pressure'bars carried by said jaws and variably operable for bending andclamping a leaf-spring, means for engagement with an edge of the spring,centrally of the latter for supporting said spring against displacementwhile permitting it to have free flexingmovements for adjustments toaccommodate itself to the adjustments of the jaws, means for adjustingsaid supporting means relatively to the jaws, and means operative in therotation'of the shaft or drum for adjusting the jaws and clamping barsfora bending and clamping action and subsequentlyretracting the same. a

2. In a machine for bending and tempering leaf-springs, the combination,with a rotatable carrier shaft or drum, of relatively fixed andadjustable pressure jaws disposed parallel with the axis of the drum andmovable in a'direction circumferentially of the drum toward and fromeach other, pressure bars carried by said jaws for bending: and clampinga spring, means for-effecting individual adjustments of the pressurebars of onejaw at'least with respect to the pressure bars of theotherjaws, a support movable radially of the drum and toward and from thejaws for engaging anedge of a spring blade and loosely supporting thesame between the jaws to prevent "displacement of the spring whilepermitting adjusting movements'thereof in the adj u'stmentof the jaws,means-for adjusting said radially adjustabl'e support, and meansoperative in the roing individualadjustments of the pressure barsof atleast one of the jaws with respect to the pressure bars of the otherjaws, a support lmovableradially; of the drum and toward and fromthe-,jawsfor engaging an edge of a spring blade centrally thereof andloosely supporting the same between the jaws to prevent displacement ofsaid spring while permitting: it to adjust itself in the (adjustments ofthe jaws, disks carried by the drum and having cam grooves, said groovesbeing engageable with said support for adjusting the latter, a lever foradjusting said disks, and meansoperative in the rotation of thedrum formoving, said aws and bars into bending and clamplng position andsubsequentlyretracting-the same.

4, In a machine for bending and tem-r peringleaf-springs, thecombination, with a rotatable carrier drum or shaft, of relatively fixedand adjustable pressure 'jaws'carried by said shaft, vrows of pressurebars carried by the jaws,the bars of at least ofv the rows-beingindividuallyadjustable with relation to the other bars, means em"-bodying fluid pressure-cylinders and pistons for respectively relativelyadjusting said jaws and bars in differentdirections, and mean forsuccessively admlttmg fluid pressure to the respective cylinders foractuating the-pistons at different points in the orbit ofrotationof theshaft or drum.

,5. In a machine for bending and tempering leaf-springs, thecombination, with a rotatable shaft or drum, of spring bending andclamping devices carried by the drum and movable toward and from eachother, fluid pressure means embodying a pair of cylindersand pistons forrespectively projecting and retracting said devices, and valve mechanism'shiftable in the rotation of the shaft or drum for successivelyadmitting fluid pressure to anddischarging fluid pressure from-therespective cylinders.

6[ In a machine for=bending and temperpering leaf-springs, thecombination, with a rotatable carrier shaft or drum, of bending andclamping devices carried by the shaft or drum and movabletoward and fromeach other, fluid pressure means embodying a pair of cylinders andpistons for respectively adjusting said devices toward and fromzeachother;"a valvedevice for admitting fluid pressure to and discha'ringfiuid pressure from the respective cylin ers, cams on the machineframe, and means connected with the valve and shifted in oppositedirections by said cams for shifting the valve .in opposite directionsat different points in the orbit of revolution of the shaft or drum.

7. In a machine for bending and tempering leaf-springs, a rotary carriershaft or drum, relatively movable jaws, sets of pressure bars on saidjaws, the bars ofone of the sets at least being individually adjust ablefor variably bending and clamping a spring edgewise radially to saidshaft or drum, asupporting member engageable with an edge of the springcentrally thereof to support it while so bent and held, means forautomatically moving said devices into and out of bending and clampingpositions at points in the rotation of the drum or shaft, and meansoperative at a point in the rotation of the drum or shaft for removingthe treated spring.

8. In a machine for bending and tempering leaf-springs, a rotary shaftor drum, relatively movablebending and clamping devices carried by andmovable with said shaft or drum, means for adjusting the same toward andfrom one another at different points in the rotation of the drum, meansfor supporting a spring leaf bent and clamped between said devices,hook-shaped ejectors engageable with the spring'leaf for engaging andremoving the same after treatvment, and means for actuating said hook-

